There are many ways you can see when SQL Server last restarted.
Method 1
The sys.dm_os_sys_info DMV contains a column that holds the startup time for SQL Server. You can run the following command to find the start time.
SELECT sqlserver_start_time FROM sys.dm_os_sys_info
Method 2
If you open the SQL Server error log in SSMS under Management > SQL Server Logs and scroll to the bottom of the error log you can see when the server was started.
Method 3
Another option is to use Windows Event Viewer to look for the startup time. If you open Windows Event Viewer and filter your Event Sources (in our case MSSQL$SQL2008) for the SQL Server instance and Event ID 17162 you can find all of the startup times that are still in the Event Viewer log.
Method 4
Another option is to use the SQL Server Dashboard Report. Right click on the server name in SSMS and select Reports > Server Reports > Server Dashboard and you will get a report
